Portable navigation devices (PNDs) that include GNSS (Global Navigation Satellite Systems) signal reception and processing functionality are well known and are widely employed as in-car or other vehicle navigation systems. Such devices include a GNSS antenna, such as a GPS antenna, by means of which satellite-broadcast signals, including location data, can be received and subsequently processed to determine a current location of the device. The PND device may also include electronic gyroscopes and accelerometers which produce signals that can be processed to determine the current angular and linear acceleration, and in turn, and in conjunction with location information derived from the GPS signal, velocity and relative displacement of the device and this vehicle in which it is typically mounted. Such sensors are most commonly provided in in-vehicle navigation systems, but may also be provided in the PND device itself.
In recent years, GPS has started to be used for pedestrian and outdoor applications. Currently there are a significant number of portable personal training devices having location determining capabilities available on the market for use e.g. in sporting activities, pedestrian travel and other outdoor applications. Portable personal training devices are devices that may be worn by runners, joggers, cyclists and other athletes and outdoor enthusiasts, etc, and which can track and record data indicative of the movement of the user over time, e.g. the pace of the user at particular moments during a workout and/or the distance covered by the user during the workout. For example, sports watches that include GPS antennas have started to be used by such users as a means to obtain real-time data of their speed, distance travelled, etc. The GPS data is also typically stored on such devices such that it can be analysed after the athlete has finished their activity, e.g. in some cases by transferring the collected data to a computer or website to be displayed as traces on a digital map (i.e. in a form of Geographic Information System (GIS)).
Such portable personal training devices can also be linked with sensors, such as a heart rate sensor (that is typically worn on a strap around a user's chest), such that heart rate data can be collected and stored on the device during a period of exercise. The collected data can then be transferred from the device to a computer or website, together with the GPS data, to allow a user to see their level of physical exertion whilst undertaking the exercise.
It is therefore known in the art to track a course for a workout, e.g. using a portable personal training device, and compare user physical parameters such as heart rate, travel time and other parameters between individuals and between separate trips for a single individual.
However, the Applicant has realised that there remains a need for a method and system that will allow routes to be proposed to users for navigation by the user under their own power, and, in particular, which involve off-road navigable segments. There is also a need for improved methods of generating an electronic map comprising off-road navigable segments.